Radiotherapy UCL Natsci Wiki
Welcome to the radiotherapy Wiki! We're a group of 4 students doing an undergraduate Natural Sciences degree at UCL on a journey of understanding the applications and history of radiation therapy, as well as learning the new directions of this treatment. Eryk Ratajczyk - First year Natural Sciences student, taking Statistics, Physics and Chemistry for the foundation course. Gabriela Silva - A Portuguese first year BSc Natural Sciences student at UCL, incredibly curious about Medical Physics and its applications in cancer treatments. Quan Gao - A first year Natural Sciences student at UCL, who really likes biology and math. Really enjoy exploring new things in radiotherapy. Unik Limbu - A Nepalese born, first year Natural Sciences student at UCL who is really interested with travelling and trying out different foods from all around the world. He is also enjoys learning Physics and is incredibly interested in the Medical Physics field of Physics. Introduction Data collect around the world shows that cancer is the second highest cause of death, having killed around 8.9 million people in 2016 Max Roser and Hannah Ritchie (2018) - "Cancer". Published online at OurWorldInData.org.Retrieved from: 'https://ourworldindata.org/cancer' Resource. In an attempt to circumvent this deadly disease, several forms of treatment have been developed throughout the years, like chemotherapy, surgery and radiotherapy, which are used in different cases to better suit the treatment of a specific type of cancer. In this Wiki page, we’ll discuss radiotherapy, which is a treatment that uses radiation to kill cancer cells by damaging their DNA’s and preventing them from proliferating through the body. This form of treatment can be used to try to cure localized cancer, make other treatments more effective or simply alleviate the pain for the patients. There are three types of radiotherapy: external beam radiation therapy, brachytherapy and radioisotope therapy; which are used in different situations as recommended by a doctor. In external beam radiation therapy, beam sources that are external to the body are aimed at the tumor to stop its growth. Meanwhile, brachytherapy is an invasive treatment that places a sealed radioactive source near the cancer and radioisotope therapy is applied through radionuclides either injected or ingested Gelband, H., P. Jha, R. Sankaranarayanan, and S. Horton, editors. 2015. Cancer. Disease Control Priorities, third edition, volume 3. Washington, DC: World Bank. doi:10.1596/978-1-4648-0349-9. License: Creative Commons Attribution CC BY 3.0 IGO. Radiotherapy uses a range of different types of radiation to make each patients treatment more effective according to different locations, sizes and types of cancer. Gamma rays, X-rays, high energy electron, neutron and proton beams and photon therapy, are some of the types of electromagnetic and particle radiation used in treatment Gianfaldoni S, Gianfaldoni R, Wollina U, Lotti J, Tchernev G, Lotti T. An Overview on Radiotherapy: From Its History to Its Current Applications in Dermatology. Open Access Maced J Med Sci. 2017;5(4):521-525. Published 2017 Jul 18. doi:10.3889/oamjms.2017.122. Even though there is a range of different options to treat cancer, the number of people dying due to the disease is alarming, so there’s still a lot of research going on to improve and develop new treatments that will be more effective in the battle against cancer, which we will discuss in this Wiki page. History After 1895 when the x-ray was discovered, its properties showed that it can be used practically in fields of researches and diagnosis of diseases, and then quickly spread in the medical field Squibb, E. H. (1900). "Brief comments on the Materia Medica and therapeutics of the year ending October 1, 1899 – Roentgen rays". Transactions of the New York State Medical Association for the year 1884–1899. New York State Medical Association. 16: 710–731. . The first attempt of using X-ray to treat cancer was in 1896 by a French physician. The experiment showed that X-ray might have an effort on reducing size of tumours and pain of the patient. But, because the patient received other treatments concurrently, the result was ultimately inconclusive Freund, Leopold (1904). Elements of general radio-therapy for practitioners. Rebman. . Until one year later, the first successful treatment was reported. Due to this, the studies about X-ray was inspired Belot, Joseph (1905). Radiotherapy in skin disease. Rebman. . Then, in 1913, William D. Coolidge invented the Coolidge tube, an improved X-ray tube capable of producing higher energy X-rays, allowing for deeper tissue penetration than what present X-ray sources allowed for. His basic design is still in use today. Soon after 1898, as Marie Curie had her husband discovered radium, the radium therapy was then developed. Three years later, Becquerel and Curie reported the physiological effects of radium rays. But, the widespread commercial exploitation of radium begun in 1913 Bright, Conrad Frederick I. (1910). "A British radium discovery". The Journal of Industrial and Engineering Chemistry. American Chemical Society. 2': 558. Moore, Richard Bishop; Kithil, Karl Ludwig (1913). "A British radium discovery". ''A preliminary report on uranium, radium, and vanadium. Govt. print. off. P79 . In the early 1900s, through experiment, it found that X-ray treatment was only useful in some certain types of cancers, and it was useless in curing pulmonary tuberculosis MacKee, George Miller (1921). X-rays and radium in the treatment of diseases of the skin. Lea & Febiger, p.20 . Meanwhile, due to the lack of knowledge of the adverse effects of X-rays, treatments often caused more harm than good. This caused panic among the public and led to a period of pessimism MacKee, George Miller (1921). X-rays and radium in the treatment of diseases of the skin. Lea & Febiger, p.20 . However, studies began into the safer use of X-rays in medicine. In the 1920s physicians began to understand that administering a fractionated dose would lead to fewer and less severe side effects. Another important development was the creation of the International Commission on Radiological Protection (ICRP) in 1928. Furthermore, in 1932 the ionization chamber was invented, which allowed for the quantitative measurement of the X-ray dose. From 1930 to 1950 (the Orthovoltage Era) much progress was made in treating deep tumours. During this period higher energy (50-200kV) tubes were developed. During the next successive three decades (the Megavoltage Era) research was partly focused on new devices which could treat cancers in deep tissues. The period also saw the birth of therapy with gamma-rays produced by cobalt-60. In the 1970s and 80s, new computerized proton beam devices entered use. By the end of the 1990s, incorporating the use of sophisticated computational methods, 3D conformal therapeutic devices were developed, allowing for very precise, high efficacy irradiation which reduced exposure to healthy tissue. In the early 20th century many studies reported the medical use of x-rays. Skin cancers were typically treated. Types of Radiation therapy There are mainly three types of radiotherapy depending on the positions of radiation source: ♦'''Brachytherapy: An invasive treatment that places a radioactive source near the cancer. ♦'Radioisotope therapy' : Patient having to either consume a radioactive fluid or is injected into their blood stream. ♦'External beam radiation therapy' : Beams of radiation is aimed towards the cancerous tumour. Uncertainties in Radiation Therapy In a radiation treatment there are several sources of uncertainty that need to be addressed, such as dosimetry reference, medical imaging of the tumour and the penetration range of the beam. The first few steps taken to plan a radiation therapy treatment for a patient is to make use of medical imaging techniques such as MRI, CT scans, PET and ultrasound, depending on the locations of the tumour, to localise the cancer From the Division of Hematology/Oncology, Department of Medicine, and Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA. The imaging processes are used to assess the target volume of the affected region as well as the delineations of the organs at risk. This tool is very important in planning the location at which the treatment will be given, as healthy tissues will likely be surrounding the tumour, so the volume of the surrounding tissues also need to be accounted for. Uncertainties can arise due to the error in calibration of the medical imaging machines, and so the location at which the the dose will be set to deliver will be deviated from true location of the tumour, possibly radiating healthy tissue. When choosing a dosage, the medical physicists and oncologist physicians must be very careful as some of the surrounding tissue will also be damaged by the treatment. Even though high dosages would be likely to kill the cancer entirely, it would also cause a lot of damage to the patients healthy tissues, as the radiation therapy would kill both cancer and healthy cells. A decision of dosage is made by weighing the benefits of killing as much of the cancer as possible against the disadvantages of damaging the surrounding healthy tissues and its cells. A dose-response curve is used to illustrate the relationship between dose and incidence of radiation at the tumour and also normal tissues, analysing the effect of the radiation on the patient. Once the dose is decided, a series of treatment sessions is planned for the patient. The way the patient is set-up for each treatment is very important, as the radiation should reach the same location in the body throughout the treatment course, so being able to reproduce the patients position during each session is crucial. However, along the treatment, the anatomy of the patient will probably change, as the tumour can become smaller or grow, so the geometry of the patient must be monitored by medical imaging. With the changes in anatomy, it is important to reanalyse the dosimetry and even the source of radiation used, as different sources have different range penetrations. To account for the uncertainties in the treatment plan, the first approach is to identify the source of errors, which as mentioned before could be due to patient positioning and change in anatomy, however it could also be due to errors in machine output calibration. When the source of errors is identified, the magnitude of the errors should be modelled as statistical distribution function, so that the errors are taken into account in dose-response analyses Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Room 7050, Bethesda, MD 20892. Economic and social impacts on radiotherapy As the cost of cancer care increases rapidly, the national budget faces increasing challenges on supporting it Aggarwal A., Ginsburg O., Fojo T. 2014. Cancer economics, policy and politics: What informs the debate? Perspectives from the EU, Canada and US. Journal of Cancer Policy, 2, pp 1-11. The increase on cancer cost is driven by increasing costs of medical or hospital care, proportion of potential patients as population aged and so on. The development of radiotherapy may also be limited due to limited national funds available. If innovation and development are supported with sufficient funds. Besides making radiation therapy more efficient, its spread would also face challenges. The new, updated radiotherapy might require new machines with higher price, lager space to place the machines and professional stuff to operate the machines. All of these factors are barriers on the way of spreading the more efficient method over hospitals. National Physics Laboratory Visit NPL does groundbreaking research in wide variety of fields including advanced manufacturing, energy and environment, life sciences and health, and many more. In particular NPL is responsible for maintaining the nation's measurement standards, having done so for over a century. We took a tour around the facilities, visiting several different labs, such as Thermal Imaging, SPECT, Airborne Nanoparticles, where we were told about some of the applicabilities of the research being done and how useful it can be if applied correctly to everyday situations. Latest activity Category:Browse Category:History